From ee1de0980f4923d3638b7355b3dc7ed32abf50ce Mon Sep 17 00:00:00 2001
From: Daniel Imms <daimms@microsoft.com>
Date: Fri, 10 Feb 2017 09:55:35 -0800
Subject: [PATCH 1/2] Perform initial viewport sync after CharMeasure is ready

Fixes #539
---
 src/Viewport.ts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/Viewport.ts b/src/Viewport.ts
index aaafbc5f..dc7ff7c3 100644
--- a/src/Viewport.ts
+++ b/src/Viewport.ts
@@ -35,7 +35,8 @@ export class Viewport {
     this.terminal.on('resize', this.syncScrollArea.bind(this));
     this.viewportElement.addEventListener('scroll', this.onScroll.bind(this));
 
-    this.syncScrollArea();
+    // Perform this async to ensure the CharMeasure is ready.
+    setTimeout(() => this.syncScrollArea(), 0);
   }
 
   /**

From 92f27d3144df75654af39e7e90b640905eae0528 Mon Sep 17 00:00:00 2001
From: Daniel Imms <daimms@microsoft.com>
Date: Mon, 13 Feb 2017 09:48:22 -0800
Subject: [PATCH 2/2] Fix tests

---
 src/Viewport.test.ts | 44 ++++++++++++++++++++++++++------------------
 1 file changed, 26 insertions(+), 18 deletions(-)

diff --git a/src/Viewport.test.ts b/src/Viewport.test.ts
index 4fa77ec0..70ee97eb 100644
--- a/src/Viewport.test.ts
+++ b/src/Viewport.test.ts
@@ -41,13 +41,17 @@ describe('Viewport', () => {
   });
 
   describe('refresh', () => {
-    it('should set the line-height of the terminal', () => {
-      assert.equal(viewportElement.style.lineHeight, CHARACTER_HEIGHT + 'px');
-      assert.equal(terminal.rowContainer.style.lineHeight, CHARACTER_HEIGHT + 'px');
-      charMeasure.height = 1;
-      viewport.refresh();
-      assert.equal(viewportElement.style.lineHeight, '1px');
-      assert.equal(terminal.rowContainer.style.lineHeight, '1px');
+    it('should set the line-height of the terminal', done => {
+      // Allow CharMeasure to be initialized
+      setTimeout(() => {
+        assert.equal(viewportElement.style.lineHeight, CHARACTER_HEIGHT + 'px');
+        assert.equal(terminal.rowContainer.style.lineHeight, CHARACTER_HEIGHT + 'px');
+        charMeasure.height = 1;
+        viewport.refresh();
+        assert.equal(viewportElement.style.lineHeight, '1px');
+        assert.equal(terminal.rowContainer.style.lineHeight, '1px');
+        done();
+      }, 0);
     });
     it('should set the height of the viewport when the line-height changed', () => {
       terminal.lines.push('');
@@ -62,17 +66,21 @@ describe('Viewport', () => {
   });
 
   describe('syncScrollArea', () => {
-    it('should sync the scroll area', () => {
-      terminal.lines.push('');
-      terminal.rows = 1;
-      assert.equal(scrollAreaElement.style.height, 0 * CHARACTER_HEIGHT + 'px');
-      viewport.syncScrollArea();
-      assert.equal(viewportElement.style.height, 1 * CHARACTER_HEIGHT + 'px');
-      assert.equal(scrollAreaElement.style.height, 1 * CHARACTER_HEIGHT + 'px');
-      terminal.lines.push('');
-      viewport.syncScrollArea();
-      assert.equal(viewportElement.style.height, 1 * CHARACTER_HEIGHT + 'px');
-      assert.equal(scrollAreaElement.style.height, 2 * CHARACTER_HEIGHT + 'px');
+    it('should sync the scroll area', done => {
+      // Allow CharMeasure to be initialized
+      setTimeout(() => {
+        terminal.lines.push('');
+        terminal.rows = 1;
+        assert.equal(scrollAreaElement.style.height, 0 * CHARACTER_HEIGHT + 'px');
+        viewport.syncScrollArea();
+        assert.equal(viewportElement.style.height, 1 * CHARACTER_HEIGHT + 'px');
+        assert.equal(scrollAreaElement.style.height, 1 * CHARACTER_HEIGHT + 'px');
+        terminal.lines.push('');
+        viewport.syncScrollArea();
+        assert.equal(viewportElement.style.height, 1 * CHARACTER_HEIGHT + 'px');
+        assert.equal(scrollAreaElement.style.height, 2 * CHARACTER_HEIGHT + 'px');
+        done();
+      }, 0);
     });
   });
 });